A computer network comprises a plurality of nodes that are connected together to allow for the exchange of data between computers located at different nodes. In most networks, certain of the computers are particularly critical and a serious degradation of functionality results if such a computer malfunctions, or otherwise is inaccessible, for an extended period of time. Not only is communication with the faulty computer interrupted, but any associated network functions performed by the computer remain unexecuted, potentially causing considerable havoc.
The magnitude of this problem can be reduced by providing two computers at each node, for example a main and a backup computer. Thus, when the main computer breaks down, the backup computer can take its place. However, implementing a system that can switch computers at the nodes can be difficult. The difficulty arises from the fact that each computer connected to the network must be identified by a unique address, and the network must be aware of the unique address of each computer in order to access it.
Prior art addressing schemes are generally cumbersome. For example, in one scheme (where a network has a main and backup computer at a first node, and a plurality of other nodes, the structure of the other nodes being unimportant), the address that the other nodes use to access the two computers at the first node must be changed from the address of the main computer to the address of the backup computer. However, this puts a large burden on each of the network nodes to recognize when the addresses must be changed.